Haemolytic anaemia in previously healthy adult patients with CMV infections: report of two cases and an evaluation of subclinical haemolysis in CMV mononucleosis.

Whereas haemolytic anaemia is commonly encountered in infants and young children with cytomegalovirus (CMV) infections, it is an infrequent complication of CMV-induced infections in previously healthy adults. The data from 2 such patients are presented. One patient's Hb fell to a level of 36 g/l, and she required prednisone and blood transfusions. Her direct antihuman globulin test (DAT) was positive (IgG), and her red blood cell survival (51Cr) revealed a T 1/2 of 5 d. Both saline-agglutinating and low-molecular-weight cold agglutinins (CA) (4 degrees C) that reacted against both cord and adult cells were identified. In the second case, a moderate haemolytic anaemia (lowest Hb 87 g/l) was accompanied by negative DAT and CA studies. 20 other patients with CMV-mononucleosis were evaluated for evidence of subclinical haemolysis. Reticulocyte counts greater than 3.0% were noted in 9 of these patients. Haptoglobin values were below 0.5 g/l in 13 patients, and a positive DAT was recorded in 3/10 cases. This study documents haemolysis in many non-immunosuppressed adult patients with CMV infections. The mechanism responsible remains obscure.